The equality the mitzvah of Shemita presents means a lot more than social justice.
The question Rashi raises at the beginning of our Parsha is so known that it has turned into an idiomatic phrase: “What does Shemita have to do with Mount Sinai, what distinguishes it from all other mitzvoth that were given at Sinai? We learn that just as Shemita was given with all its rules and details - all the mitzvoth were given at Sinai with their rules and details, this is how it was related in Torat Kohanim“.
However, there is a strong contrast between Mount Sinai and Shemita. The latter is a mitzvah that is dependent on our control of the land (of Israel), and the land’s holiness. Furthermore - as the Torah will teach us later on, in admonishing us, the nation’s exile is punishment for violating this specific mitzvah: “Than shall the land be given its Sabbath as long as she lays desolate, and you in the land of your enemies, than shall the land rest, and repay her Sabbaths. All her desolate days she will have rest, the rest she didn’t have on your Sabbaths…” (Leviticus 26, 34-35). On the other hand, we have Mount Sinai, which is not Eretz Israel, and holds no holiness on its own: “at the sound of the horns they may come up the mountain” - at the end of the revelation at Mount Sinai, after Hashem gave us the Torah, Mount Sinai become, once again, a mountain like all other mountains.
What, if so, is the connection between Shmita and Mount Sinai? Already many years ago, stood an old man, Rav Shach Z”L, and cried out that Am Israel’s nationality was decided at Mount Sinai, and they became a nation when they accepted the Torah, even before coming to Eretz Israel. Our homeland is the Torah; Eretz Israel is a mitzvah just like Tefillin and Tzitzit no different than any other, and Territory is not necessary - not for Am Israel’s existence, nor for our self-identity.
We, as Religious-Zionists, believe that complete Jewish existence is unobtainable outside of Eretz Israel, and this mitzvah does not share the same status of other mitzvoth, even so, there is much truth to Rav Shach’s words. The Torah fights against the ‘native’ character, ‘the people of the land’, and their grasp of the meaning of land. All were deeply connected to idolism. The mitzvah of Shemita creates a fundamental alienation, an ongoing estrangement between the Jew and his land. There is never complete congruence between him and his place; he can never be completely ‘down to earth’. The Torah’s ultimate demand is to perpetuate the knowledge that “Land is mine, for you are but strangers and settlers of mine” (25, 26) - this is the condition for staying in this land. The ability to let loose on the seventh year, to return the land on the fiftieth year jubilee (Yovel), is the only justification we have for not going into actual exile. Similarly, says the Gur Rabbi in his book, the Sefat Emet:
Truly, in this world Bnei-Israel have no permanent dwelling, therefore ‘we were slaves in Egypt’ etc., because this is not our place. And all nations have a place, but Bnei-Israel’s place is above nature, time and space. Indeed when the Temple was destroyed and we were exiled, we had no existence in this world. But when Hashem, blessed be he, raised us of our bondage to become like sons, he gave us existence in the ways of Torah… then we were given a place in the world.
Dialectically Am Israel can hang on to the land and preserve its sanctity, only by accepting an exilic awareness in the land itself. Otherwise this sanctity can easily deteriorate to fetishism. Hence we find that the sanctity of Sinai (exile) is the source for the sanctity of Eretz Israel.
Moreover: we mustn’t forget that the mitzvah of Shemita, which is, as stated, an expression of Eretz Israel‘s sanctity, is in essence a mitzvah of social justice and economic equality. Equality and freedom are the values that stand at the core of this mitzvah and are therefore the most significant of symbols regarding our nation’s situation in Eretz Israel. But, as opposed to the modern world of values, the basis for our social and moral relationship is holiness. Shemita establishes equality, much broader than social equality, it may be said that it reaches a level of ecological equality: “and the Sabbath-produce of the land will be food for you, for you and your slave, and maid, and your hired workers, and the settlers livings amongst you. And for your cattle and the beasts of the land, shall have the produce for food” (25, 6-7). Imagine a partnership between a farmer and his ox - both have equal rights over the produce of the land. Shemita‘s radicalism is almost inconceivable. It goes without saying that the sanctity of Eretz Israel means justice and equality in the ownership and use of the land. And indeed, many obligations and prohibitions in the Parsha, like the prohibitions on interest and fraud, the mitzvoth involved with redeeming land and Tzedaka, come to establish a just society, to prevent unfair exploitation of the weak and battle offensive capitalism. All these are fixed in holiness, and in this context morality is holiness.
The Torah merges holy rites with holy morals. The merge causes a dual effect: as stated, it raises a barrier preventing the collapse of holy rites to fetishism; but also morality gains the weight, profundity and reality of the holy rites.